Correct option is C
A cylindrical ring gauge is a precision tool used to check the external diameter of shafts and ensure dimensional accuracy in manufacturing. To measure its internal diameter accurately, a pneumatic comparator is the most suitable instrument.
· Pneumatic comparators work by measuring the air pressure variations caused by the clearance between the gauge and the internal surface of the ring.
· They provide high-precision, non-contact measurements with an accuracy of up to 0.001 mm or better.
· They are commonly used in inspection labs and quality control processes for highly precise internal diameter measurements.
Working Principle of Pneumatic Comparators:
· Air flows through a nozzle placed inside the cylindrical ring gauge.
· Changes in air pressure indicate deviations in the internal diameter.
· The pressure readings are converted into precise dimensional measurements.
